This invention relates to the testing of the condition of an electric circuit at a location remote from that circuit and in one of its aspects to a remote live circuit tester.
Electricians, air conditioner repairmen, and others working with electrical systems such as those in homes or offices frequently need to turn power off in certain circuits such as turning the power off at a certain wall receptacle or at a thermostat. Normally, the power needs to be turned off at a fuse box or breaker box which is not within sight of the circuit in question. The repairman thus begins an iterative routine of turning off the breaker which he believes is the correct one and then returning to the circuit in question and testing that circuit with his voltmeter. If the voltmeter indicates that the power is still on at that circuit, then the repairman returns to the breaker box, turns on the breaker just turned off and turns off a different breaker. He then returns to the circuit in question and again tests that circuit with his voltmeter. Regularly, this leads to extreme situations such as when the circuit in question can only be accessed from the attic or from on top of the roof of the house. Regularly, this leads to multiple trips up and down a ladder and in an out of a house.
It is thus an object of this invention to save the time of people working with electricity by providing a method for determining the condition of a circuit at a location remote from that circuit.
The apparatus of this invention includes a transmitter with an output responsive to the circuit to be tested. The output of the transmitter has a plurality of states corresponding to the various states of interest of the circuit to be tested such as a state of transmitting a constant signal when power is on and a state of not transmitting any signal corresponding to when power is off.
The tester of this invention also includes a receiver which is responsive to the output states transmitted from the transmitter and an indicator responsive to the states received by the receiver. The indicator includes some form of indicating device such as a light or a meter.
Thus, a remote live circuit tester according to this invention will include a transmitter which can be plugged into the outlet in question or connected across the terminals in question and left while a repairman takes the combination receiver-indicator with him to the breaker box. As long as the circuit in question has power to it, and the receiver-indicator is turned on, the indicator will indicate to the repairman that the circuit is still live. When the repairman turns off the correct breaker, then the indicator will indicate that power to the circuit has been turned off. The repairman can then return to the circuit in question and as an added safety precaution, test the circuit with his voltmeter.